Talkingpeace "RE IS NOT COMPULSORY
FFS how many times in one week do I have to post the links."
Yes it is.
It is compulsory / there is a legal entitlement for schools to provide Religious Education. This is stated in the 1944 education act and reinforced in the 1988 education act. The government non stat guidance on RE from 2010 also states:
"The legal basis of RE in the curriculum of maintained schools
Every maintained school in England must provide a basic curriculum (RE, sex education and the National Curriculum). This includes provision for RE for all registered pupils at the school (including those in the sixth form), except for those withdrawn by their parents (or withdrawing themselves if they are aged 18 or over) in accordance with Schedule 19 to the School Standards and Framework Act 1998."
This covers all type of schools including academies and free schools as the 2013 Religious Education Council report states:
"RE is a statutory subject of the school curriculum of maintained schools. Academies and free schools are contractually required through the terms of their funding to make provision for the teaching of RE to all pupils on the school roll."
Now RE is part of the basic curriculum (but has never been part of the national curriculum). There is guidance given as to how much RE should be taught in schools (5% of curriculum time at KS4), but this does not have to be done on a weekly basis, and at KS4 does not have to be an examined course. Therefore, schools can opt to simply do a weekly non examined course in RE and that is legal. The school can also choose to combine RE with other subjects (such as part of a humanities course, or with PSHE) or it could do this through special off timetable days whereby students do not follow their timetable for the day, but instead follow a Religious Education programme for the day. This would all fulfil the legal obligation. The 2010 OFSTED document transforming Religious Education notes that:
"27. Non-accredited courses took a variety of forms. In some schools, for example, RE formed part of a carousel of units, together with personal, social, health, and economic education and citizenship. In other schools, the normal timetable would be suspended from time to time and a whole day devoted to considering aspects of religion and belief. These days were particularly successful when they were led by a team of teachers, who were committed to using high quality resources, a variety of media sources and outside speakers to engage students in lively discussion."
However, over the past few years, various changes (such as the non inclusion of RE in the EBACC) has meant that curriculum time given to RE has been squeezed and lots of schools are no longer fulfilling their legal obligation. There are lots of reports about this.
Of course, parents have the right to withdraw their children from RE, and this is enshrined in law and has been since 1944.
So, to get back to the OP.
If the school is not providing any form of RE at KS4, then it is breaking its legal obligation. However, before you complain I would check that it is not fulfilling that requirement through another course or through special RE days.
Collective Worship is something completely different, and cannot form the basis of RE.